Add optimization to get a11y next word

microsoft · Sep 30, 2020 · b6fb987 · b6fb987
1 parent 9b1ee57
commit b6fb987
Show file tree

Hide file tree

Showing 2 changed files with 22 additions and 36 deletions.
diff --git a/src/buffer/out/textBuffer.cpp b/src/buffer/out/textBuffer.cpp
@@ -1126,7 +1126,8 @@ const COORD TextBuffer::GetWordEnd(const COORD target, const std::wstring_view w
 
     if (accessibilityMode)
     {
-        return _GetWordEndForAccessibility(target, wordDelimiters);
+        const auto lastCharPos{ GetLastNonSpaceCharacter() };
+        return _GetWordEndForAccessibility(target, wordDelimiters, lastCharPos);
     }
     else
     {
@@ -1139,13 +1140,20 @@ const COORD TextBuffer::GetWordEnd(const COORD target, const std::wstring_view w
 // Arguments:
 // - target - a COORD on the word you are currently on
 // - wordDelimiters - what characters are we considering for the separation of words
+// - lastCharPos - the position of the last nonspace character in the text buffer (to improve performance)
 // Return Value:
 // - The COORD for the first character of the next readable "word". If no next word, return one past the end of the buffer
-const COORD TextBuffer::_GetWordEndForAccessibility(const COORD target, const std::wstring_view wordDelimiters) const
+const COORD TextBuffer::_GetWordEndForAccessibility(const COORD target, const std::wstring_view wordDelimiters, const COORD lastCharPos) const
 {
     const auto bufferSize = GetSize();
     COORD result = target;
 
+    // Check if we're already on/past the last RegularChar
+    if (bufferSize.CompareInBounds(result, lastCharPos, true) >= 0)
+    {
+        return bufferSize.EndExclusive();
+    }
+
     // ignore right boundary. Continue through readable text found
     while (_GetDelimiterClassAt(result, wordDelimiters) == DelimiterClass::RegularChar)
     {
@@ -1155,6 +1163,12 @@ const COORD TextBuffer::_GetWordEndForAccessibility(const COORD target, const st
         }
     }
 
+    // we are already on/past the last RegularChar
+    if (bufferSize.CompareInBounds(result, lastCharPos, true) >= 0)
+    {
+        return bufferSize.EndExclusive();
+    }
+
     // make sure we expand to the beginning of the NEXT word
     while (_GetDelimiterClassAt(result, wordDelimiters) != DelimiterClass::RegularChar)
     {
@@ -1256,44 +1270,16 @@ void TextBuffer::_PruneHyperlinks()
 // - pos - The COORD for the first character on the "word" (inclusive)
 bool TextBuffer::MoveToNextWord(COORD& pos, const std::wstring_view wordDelimiters, const COORD lastCharPos) const
 {
-    auto copy = pos;
-    const auto bufferSize = GetSize();
+    // move to the beginning of the next word
+    // NOTE: _GetWordEnd...() returns the exclusive position of the "end of the word"
+    //       This is also the inclusive start of the next word.
+    auto copy{ _GetWordEndForAccessibility(pos, wordDelimiters, lastCharPos) };
 
-    // Already at the end. Can't move forward.
-    if (pos == bufferSize.EndExclusive())
+    if (copy == GetSize().EndExclusive())
     {
         return false;
     }
 
-    // started on a word, continue until the end of the word
-    while (_GetDelimiterClassAt(copy, wordDelimiters) == DelimiterClass::RegularChar)
-    {
-        if (!bufferSize.IncrementInBounds(copy))
-        {
-            // last char in buffer is a RegularChar
-            // thus there is no next word
-            return false;
-        }
-    }
-
-    // we are already on/past the last RegularChar
-    if (bufferSize.CompareInBounds(copy, lastCharPos) >= 0)
-    {
-        return false;
-    }
-
-    // on whitespace, continue until the beginning of the next word
-    while (_GetDelimiterClassAt(copy, wordDelimiters) != DelimiterClass::RegularChar)
-    {
-        if (!bufferSize.IncrementInBounds(copy))
-        {
-            // last char in buffer is a DelimiterChar or ControlChar
-            // there is no next word
-            return false;
-        }
-    }
-
-    // successful move, copy result out
     pos = copy;
     return true;
 }

diff --git a/src/buffer/out/textBuffer.hpp b/src/buffer/out/textBuffer.hpp
@@ -224,7 +224,7 @@ class TextBuffer final
     const DelimiterClass _GetDelimiterClassAt(const COORD pos, const std::wstring_view wordDelimiters) const;
     const COORD _GetWordStartForAccessibility(const COORD target, const std::wstring_view wordDelimiters) const;
     const COORD _GetWordStartForSelection(const COORD target, const std::wstring_view wordDelimiters) const;
-    const COORD _GetWordEndForAccessibility(const COORD target, const std::wstring_view wordDelimiters) const;
+    const COORD _GetWordEndForAccessibility(const COORD target, const std::wstring_view wordDelimiters, const COORD lastCharPos) const;
     const COORD _GetWordEndForSelection(const COORD target, const std::wstring_view wordDelimiters) const;
 
     void _PruneHyperlinks();